Hemstitch-sewing machine



M y 28, 1929- G. M. EAMES ET AL HEMSTITCH SEWING MACHINE Filed March 12, 1928 2 Sheets-Sheet ENTOR GewyeMEZ mw and John 6. Bin e Patented May 28, 1929.

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GEORGE MrEAMES, OF BRIDGEPORT, AND JOHN HINGE; OF STRATFORD, CONNECTI- CUT, ASSIGNOBS TO THE SINGER MANUFACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY. 4

HEMSTI'IC I -SEWING MACHINE.

Application filed. March 12, 1928. -Serial No. 260,835.

This invention relates to improvements in needle-vibrating mechanisms for multipleneedle hemstitching machines and has for its primary object to increasethe range of use of hemstitching machines employing a needle-vibrating-mechanism which is durable at high speed operation and capable of maintaining the accuracy of operation essential in hemstitching machines producing accept able work.

For certain classes of work it is essential that the extent of vibration of one needle be greater than that of the other needle and it has heretofore been a common practice in two-needle hemstitching machines to vibrate the, needles by means of separate pitmen each adjustably connected with a cam-actuated segment, whereby theextent of lateral l vibration of each needle could be determined independentlyof the extent of vibration of the other needle. To meet the modern demands of high speed operation of machines, the present invention aims to providea mechanism whereby the needles are both vibrated:

correction for the inner positions of the needles.

To this end, the reciprocatory pitman is suitably connected with one arm of a bellcrank lever, fulcrumed upon the machine frame and of which the other arm is connected by separate links with actuating arms each secured upon a rock-shaft for adjustment transversely of the axis of the rockshaft. The rock-shafts are journaled in the machine frame and each carries a crankarmwhich is clamped upon its rock-shaft to permit of adjustment of each crank-arm about the longitudinal axis of its rock-shaft. These crank-arms carry swivel-joints which as usual are slidingly entered by needle guide-rods fulcrumed upon a supporting plate at the lower endof the needle-bar and carrying the needles. The line of adjustment of each of the rock-shaft actuating arms closely approaches the arc of movement of the point of pivotal connection of each actuating-arm with its operating link and therefore only a slight correction is required of the needle-position following upon adjustment of an actuating arm. This correction may be readily obtained by reason of the dle-actuating mechanism. Fig.2 is a frontend elevation, partly in section, of the head of the machine bracket-arn1. Fig. 3 is a.

front side elevation of the bracket-arm head. Flg. 1 comprises detail perspective views of one of the needle-vibrating. rock-shafts and its actuating arm.

The hemstitching 'machine' illustrated in V the drawings has the usual framework in-' cluding the cloth-plate 1 from which rises the hollow standard 2 of the overhanging bracket-arm 3 terminating in-the head 4. Journaled in suitable bearings provided in the shaft 5 carrying at one end the belt-pulley 6 and at its opposite end the crank-disk 7 connected in the .usual manner by means of overhanging bracket-arm is the .rotarymainf a link 8 with the needle-bar 9 jo'urnaled for vertical reciprocation in bearings provided in the head 1. The needle-barf) carries. at its lower end a supporting plate 10 pivotally sustaining a pair of needle'carriers 11 and 12. ,The needle-carrier 11 comprises. an

I apertured sleeve 13 supported for oscillation uponv a shouldered pivot-bolt 14;, passing through an elongated aperture 15 provided in the plate 10 and secured upon said'plate by means of a nut 16 and washer 17, As

will be evident, this construction provides for a lateral adjustment of the pivot-axis of the needle-carrier upon the plate 10. Depending from the needle-carrier sleeve 13 is a clamp 18 for the shank-of aneedle 19secured therein by means of a clamp-screw 20.

, Another clamp 21 integrally rising from the sleeve 13 is provided with an aperture receiving the lower end of a substantially vertically disposed guide-rod 23, secured in said clamp 21 by means of a screw24.- Needlecarrier 12 is similar to the described carrier 11 in construction and in its pivotal support. Clamped to the needle-carrier 12 is a needle 25 and a substantially vertically disposed guide-rod 26, the supporting means for the needles and the guide-rods being evidently suchas to cause them to partake of the vertical reciprocations of the needle-bar.

The guide-rod 23 slidingly enters a transversely apertured swivel-pin 27 mounted within a lateral boss 28 on the free end of a crank-arm 29, disposed at the front of the bracket-arm head 4 and clamped uponta rock-shaft- 30. The rock-shaft 30 has a subface of an actuating arm 35, the base of the guideway. 34 being provided with a slot 36 elongated in the direction of the length of the guideway. The head 32 of the rockshaft is provided with an axially extending aperture 37 threaded to receive a securing screw 38 passing through the slot 36 and it is therefore evident'that the crank-arm 29, rockhaft 30 and actuating arm 'constitute in effect'abell-crank lever having a substantial journal in the machine frame. lhe guide-rod 26 is similarly connected with a swivel-pin 39 within the boss 40 on a crankarm 41 clampedto a rock-shaft 42 journaled in the head 4. Adjustably secured upon the rearward end of the rock-shaft 42, in a manner similar to the securing means for the actuating arm 35, is an actuating arm '43.

The actuating arms 35 and 43 are substantially horizontal, their free ends being directed toward each other and carrying pivot-pins 44 and 45 separately connected by equal length links 46 and 47 with an arm 48 of an elbow lever fulcrumed upon a pivotpin 49 suitably fixed in the head 4. The links 46 and 47 have a coaxial pivotal connection with lateral projections 50 on the V arm 48 of the elbow-lever, the other arm 51 thereof having an adjustable pivotal-connection with one end of a pitman 52 of which the) opposite end hasa similar connection with a slide-block 53. The slideblock 53 is secured for adjustment lengthwise of the channeled face of a vibratory arm 54 fulcrumed upon a shaft 55 journaled in the standard 2, said arm 54 being suitably vibrated by means of a grooved camr56 rotated once for every'three rotations of the main-shaft!) through intermeshing gears 57 and 58.

Any suitable mechanism complemental to the needles in the formation of lock-stitches may be employed and the present disclosure 3 is therefore confined to the needle-actuating mechanism described.

It will be apparent from the foregoing description that ,theextent of lateral vibration of either of the needles may be readily 'tory needle-bar, a needle-carrier having a needle guide-rod pivotally supported upon varied by adjustment of either of the actuating arms 35 and 43 transversely of the axes of their respective rock-shafts and that the inner positions of the needles may be accurately determined by adjustment of the crank-arms 29 and 41 about their rock-shaft axes, thereby con' pensating for any slight rocking. movements of the shafts 30 and 42 occasioned by adjustment of the arms 35 and 43. I

Having thus set forth the nature of the invention, what we claim herein is 1. A needle-actuating mechanism for hemstitching machines, comprising a reciprocasaid needle-bar, a bell-crank lever operative- I ly connected with said guide-rod,means permitting adjustment of one of the arms of said bell-crank lever transversely of the axis of said lever and of the other arm of said lever about the axis, thereof, and means for rocking said lever to impart vibratory movements to said needle guide-rod. 2. In a hemstitch sewingmachine having a cloth-plate and an overhanging bracket arm, a needle-actuating mechanism comprising a reciprocatory needle-bar, a needle-carrier having a needle guide-rod pivotally sup-1 ported upon said needle-bar, a rock-shaft secured upon said rock-shaft for adjustment about the axisof said shaft, an actuating arm secured upon said rock-shaftfor adjustment transversely of the axis of said shaft, an operative connection between said crank-arm and the needle guide-rod, and means for operating said actuating arm to thereby vibrate the needle guide-rod. 3. Needle actuating mechanism for twoneedle hemstitching machines, comprising a reciprocatory needle-bane pair of needlecarriers having-needle guide-rods pivotally supported upon said needle-bar, a pair of crank-arms operatively connected with said vjournaled in said bracket-arn'na cran'k arm guide rods permitting endwise movements N thereof and adapted to impart vsidewise movements thereto, a pair of rock-shafts carrying said crank-arms, a reciprocatory pitman, and operative connections for imparting rocking movements to both of said rock-shafts from said pitman including means for varying the throw of one rockshaft with respect to the throw of the other[ v 4. Needle actuating mechanism for twoneedle hemstitching machines, comprising a pair of reciprocatory needles, means for reciprocating said needles, a reciprocatory pitman, and operative connections for lateracllly vibrating both of said needles from sai the lateral throw of one needle with respect to the lateral throw of the other. i

5. Needle actuat'ing'mechanism for twopitman, including meansf-or varying v needle hemstitching machines, comprising a pair of reciprocatory needles, means for reciprocating said needles, a reciprocatory pitman, and operative connections for laterally vibrating both of said needles from said pitman, including means for varying the lateral throw of either needle with respect to the lateral throw of the other.

6. In a hemstitch sewing-machine having a cloth-plate and an overhanging bracketarm, a needleactuating mechanism comprising areciprocatory needle-bar, a pair of needle-carriers pivotally supported upon said needle-bar, a pair of rock-shafts journaled in said bracket-arm, operative COI1Il6C-,

tions between said rock-shafts and the needle-carriers for imparting vibratory movements to said carriers, and operating mechanism for said rock-shafts including actuating arms secured upon said rock-shafts for adjustment transversely of the axes of said rock-shafts to thereby vary the throw of bar, a rock-shaft journaled in said bracketarm, operative connections between said rock-shaft and the needle-carrierfor imparting vibratory movements to said carrier, an actuating lever fulcrumed upon the free end of said bracket-arm means for actuating said lever, and operative connections be- V tween said lever and said rock-shaft including means for adjusting the extent of rocking movement of said shaft with respect to the extent of movement of said lever.

I In testimony whereof, we have signed our names to this specification.

- GEORGE M. EAMES.

JOHN C. HINGE. 

